what the hell is a nug i keep hearin people say it but i dunno what it means. im good on most other words its just this one i got trouble with.
1 Improper use of contact lenses or steroid eyedrops can lead to fungal infections, which in turn can cause corneal ulcers. Also, a corneal injury that results in plant material getting into the eye can lead to fungal keratitis.  Acanthamoeba are microscopic, single-celled amoeba that can cause human infection.
Report Abuse. Most minor, single mouth ulcers are caused by damage to the mouth. For example, you may accidentally bite the inside of your cheek while you are eating. Damage to your mouth can also occur if you use a toothbrush incorrectly, or from a sharp tooth, or filling. Recurrent mouth ulcers The cause of recurrent mouth ulcers is often unknown. However, there are a number of factors which may increase the chances of you getting recurrent ulcers.